目的 电化学合成过氧化氢(H_2O_2)是一种极具应用前景的分散式生产方法, 但因传统的单极电合成电流效率不高, 其发展受到了严重限制。本文旨在通过自组装单层膜修饰碳纤维纸制备高效二电子水氧化合成过氧化氢的阳极, 同时耦合负载聚四氟乙烯/炭黑的自然空气扩散阴极, 实现阴阳极同步电合成过氧化氢, 从而大幅度提高其电流效率。 创新点 1. 通过自组装单层膜修饰碳纤维纸制备功能化阳极高效二电子水氧化合成过氧化氢; 2. 耦合阳极和阴极大幅度提高电合成过氧化氢的电流效率。 方法 1. 利用自组装单层膜修饰碳纤维纸制备功能化阳极, 通过物化性能表征确定电极的结构特征(图1), 并通过活性、选择性等指标考察电极的二电子水氧化性能(图2); 2. 制备负载聚四氟乙烯/炭黑的自然空气扩散阴极, 并通过电化学性能表征确定最佳的物料配比(图3); 3. 耦合功能化阳极和自然空气扩散阴极, 并通过电流效率、产率、稳定性等指标评估体系电合成过氧化氢的性能(图4和表1)。 结论 1. 利用自组装单层膜修饰碳纤维纸制备高效的二电子水氧化阳极; 阳极过氧化氢的选择性为62.1%, 产率为12.6 µmol/(min·cm^2)。2. 确定自然空气扩散阴极上聚四氟乙烯与炭黑的比例为0.6, 并将其与功能化阳极耦合同步电合成过氧化氢, 所得电流效率高达152.9%, 且产率达到38 µmol/min。 Electrosynthesis of hydrogen peroxide (H_2O_2) is a decentralized production method with excellent application prospects. Coupling anodes with cathodes can achieve highly efficient electrosynthesis of hydrogen peroxide. In this study, we prepared an anode for H_2O_2 electrosynthesis via the two-electron water oxidation reaction (2e-WOR) by modifying carbon fiber paper with self-assembling monolayers. In addition, a natural air-diffused cathode loaded with polytetrafluoroethylene/carbon black using carbon cloth as substrate was prepared to combine with the modified anode to produce H_2O_2 simultaneously. The total current efficiency of the anode and cathode reached 152.9%, and the H_2O_2 production rate was as high as 38 µmol/min at 2.8 V vs. reversible hydrogen electrodes (RHE) in a Nafion 117 membrane-separated electrolyzer. This work reported a novel carbon-based 2e-WOR catalyst and laid a theoretical foundation for the simultaneous electrosynthesis of H_2O_2 with an anode and cathode.
目的 电化学合成过氧化氢(H_2O_2)是一种极具应用前景的分散式生产方法, 但因传统的单极电合成电流效率不高, 其发展受到了严重限制。本文旨在通过自组装单层膜修饰碳纤维纸制备高效二电子水氧化合成过氧化氢的阳极, 同时耦合负载聚四氟乙烯/炭黑的自然空气扩散阴极, 实现阴阳极同步电合成过氧化氢, 从而大幅度提高其电流效率。 创新点 1. 通过自组装单层膜修饰碳纤维纸制备功能化阳极高效二电子水氧化合成过氧化氢; 2. 耦合阳极和阴极大幅度提高电合成过氧化氢的电流效率。 方法 1. 利用自组装单层膜修饰碳纤维纸制备功能化阳极, 通过物化性能表征确定电极的结构特征(图1), 并通过活性、选择性等指标考察电极的二电子水氧化性能(图2); 2. 制备负载聚四氟乙烯/炭黑的自然空气扩散阴极, 并通过电化学性能表征确定最佳的物料配比(图3); 3. 耦合功能化阳极和自然空气扩散阴极, 并通过电流效率、产率、稳定性等指标评估体系电合成过氧化氢的性能(图4和表1)。 结论 1. 利用自组装单层膜修饰碳纤维纸制备高效的二电子水氧化阳极; 阳极过氧化氢的选择性为62.1%, 产率为12.6 µmol/(min·cm^2)。2. 确定自然空气扩散阴极上聚四氟乙烯与炭黑的比例为0.6, 并将其与功能化阳极耦合同步电合成过氧化氢, 所得电流效率高达152.9%, 且产率达到38 µmol/min。 Electrosynthesis of hydrogen peroxide (H_2O_2) is a decentralized production method with excellent application prospects. Coupling anodes with cathodes can achieve highly efficient electrosynthesis of hydrogen peroxide. In this study, we prepared an anode for H_2O_2 electrosynthesis via the two-electron water oxidation reaction (2e-WOR) by modifying carbon fiber paper with self-assembling monolayers. In addition, a natural air-diffused cathode loaded with polytetrafluoroethylene/carbon black using carbon cloth as substrate was prepared to combine with the modified anode to produce H_2O_2 simultaneously. The total current efficiency of the anode and cathode reached 152.9%, and the H_2O_2 production rate was as high as 38 µmol/min at 2.8 V vs. reversible hydrogen electrodes (RHE) in a Nafion 117 membrane-separated electrolyzer. This work reported a novel carbon-based 2e-WOR catalyst and laid a theoretical foundation for the simultaneous electrosynthesis of H_2O_2 with an anode and cathode.
{"title":"Coupling functional anodes with natural air-diffused cathodes enables highly efficient hydrogen peroxide electrosynthesis","authors":"C. Ling, Aiping Liang, Chaolin Li, Wenhui Wang","doi":"10.1631/jzus.A2200566","DOIUrl":"https://doi.org/10.1631/jzus.A2200566","url":null,"abstract":"目的 电化学合成过氧化氢(H_2O_2)是一种极具应用前景的分散式生产方法, 但因传统的单极电合成电流效率不高, 其发展受到了严重限制。本文旨在通过自组装单层膜修饰碳纤维纸制备高效二电子水氧化合成过氧化氢的阳极, 同时耦合负载聚四氟乙烯/炭黑的自然空气扩散阴极, 实现阴阳极同步电合成过氧化氢, 从而大幅度提高其电流效率。 创新点 1. 通过自组装单层膜修饰碳纤维纸制备功能化阳极高效二电子水氧化合成过氧化氢; 2. 耦合阳极和阴极大幅度提高电合成过氧化氢的电流效率。 方法 1. 利用自组装单层膜修饰碳纤维纸制备功能化阳极, 通过物化性能表征确定电极的结构特征(图1), 并通过活性、选择性等指标考察电极的二电子水氧化性能(图2); 2. 制备负载聚四氟乙烯/炭黑的自然空气扩散阴极, 并通过电化学性能表征确定最佳的物料配比(图3); 3. 耦合功能化阳极和自然空气扩散阴极, 并通过电流效率、产率、稳定性等指标评估体系电合成过氧化氢的性能(图4和表1)。 结论 1. 利用自组装单层膜修饰碳纤维纸制备高效的二电子水氧化阳极; 阳极过氧化氢的选择性为62.1%, 产率为12.6 µmol/(min·cm^2)。2. 确定自然空气扩散阴极上聚四氟乙烯与炭黑的比例为0.6, 并将其与功能化阳极耦合同步电合成过氧化氢, 所得电流效率高达152.9%, 且产率达到38 µmol/min。 Electrosynthesis of hydrogen peroxide (H_2O_2) is a decentralized production method with excellent application prospects. Coupling anodes with cathodes can achieve highly efficient electrosynthesis of hydrogen peroxide. In this study, we prepared an anode for H_2O_2 electrosynthesis via the two-electron water oxidation reaction (2e-WOR) by modifying carbon fiber paper with self-assembling monolayers. In addition, a natural air-diffused cathode loaded with polytetrafluoroethylene/carbon black using carbon cloth as substrate was prepared to combine with the modified anode to produce H_2O_2 simultaneously. The total current efficiency of the anode and cathode reached 152.9%, and the H_2O_2 production rate was as high as 38 µmol/min at 2.8 V vs. reversible hydrogen electrodes (RHE) in a Nafion 117 membrane-separated electrolyzer. This work reported a novel carbon-based 2e-WOR catalyst and laid a theoretical foundation for the simultaneous electrosynthesis of H_2O_2 with an anode and cathode.","PeriodicalId":17508,"journal":{"name":"Journal of Zhejiang University-SCIENCE A","volume":"52 1","pages":"377-386"},"PeriodicalIF":3.2,"publicationDate":"2023-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90672063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reeya Agrawal, Anjan Kumar, Mustafa K. A. Mohammed, Sangeeta Singh
当患者体内的受损器官/组织被修复/替代后，患者的生活质量将会得到大幅改善。用于人体植入性治疗的生物材料必须具备特定的性能。人体对生物材料的接受程度是决定器官修复/移植成败的关键因素。最新的生物材料的结构应与组织内的结构相似。当前，基于先进的抗污、杀菌及抗生物膜技术，研究者正在研发抗感染的生物材料；它在现代医疗中预防和治疗重大传染性疾病是不可或缺的。这些对生物材料提出了新的要求。将来的研究热点之一是制备人体植入物的材料，并添加金属、陶瓷及聚合物。这篇综述涵盖了组织工程所需的生物材料的概念、关键特征以及生物材料（包括生物活性材料和生物可吸收材料）在医疗实践中的应用，并将会帮助研究者更好地选取生物材料。 Biomaterial research has been going on for several years, and many companies are heavily investing in new product development. However, it is a contentious field of science. Biomaterial science is a field that combines materials science and medicine. The replacement or restoration of damaged tissues or organs enhances the patient’s quality of life. The deciding aspect is whether or not the body will accept a biomaterial. A biomaterial used for an implant must possess certain qualities to survive a long time. When a biomaterial is used for an implant, it must have specific properties to be long-lasting. A variety of materials are used in biomedical applications. They are widely used today and can be used individually or in combination. This review will aid researchers in the selection and assessment of biomaterials. Before using a biomaterial, its mechanical and physical properties should be considered. Recent biomaterials have a structure that closely resembles that of tissue. Anti-infective biomaterials and surfaces are being developed using advanced antifouling, bactericidal, and antibiofilm technologies. This review tries to cover critical features of biomaterials needed for tissue engineering, such as bioactivity, self-assembly, structural hierarchy, applications, heart valves, skin repair, bio-design, essential ideas in biomaterials, bioactive biomaterials, bioresorbable biomaterials, biomaterials in medical practice, biomedical function for design, biomaterial properties such as biocompatibility, heat response, non-toxicity, mechanical properties, physical properties, wear, and corrosion, as well as biomaterial properties such surfaces that are antibacterial, nanostructured materials, and biofilm disrupting compounds, are all being investigated. It is technically possible to stop the spread of implant infection.
当患者体内的受损器官/组织被修复/替代后，患者的生活质量将会得到大幅改善。用于人体植入性治疗的生物材料必须具备特定的性能。人体对生物材料的接受程度是决定器官修复/移植成败的关键因素。最新的生物材料的结构应与组织内的结构相似。当前，基于先进的抗污、杀菌及抗生物膜技术，研究者正在研发抗感染的生物材料；它在现代医疗中预防和治疗重大传染性疾病是不可或缺的。这些对生物材料提出了新的要求。将来的研究热点之一是制备人体植入物的材料，并添加金属、陶瓷及聚合物。这篇综述涵盖了组织工程所需的生物材料的概念、关键特征以及生物材料（包括生物活性材料和生物可吸收材料）在医疗实践中的应用，并将会帮助研究者更好地选取生物材料。 Biomaterial research has been going on for several years, and many companies are heavily investing in new product development. However, it is a contentious field of science. Biomaterial science is a field that combines materials science and medicine. The replacement or restoration of damaged tissues or organs enhances the patient’s quality of life. The deciding aspect is whether or not the body will accept a biomaterial. A biomaterial used for an implant must possess certain qualities to survive a long time. When a biomaterial is used for an implant, it must have specific properties to be long-lasting. A variety of materials are used in biomedical applications. They are widely used today and can be used individually or in combination. This review will aid researchers in the selection and assessment of biomaterials. Before using a biomaterial, its mechanical and physical properties should be considered. Recent biomaterials have a structure that closely resembles that of tissue. Anti-infective biomaterials and surfaces are being developed using advanced antifouling, bactericidal, and antibiofilm technologies. This review tries to cover critical features of biomaterials needed for tissue engineering, such as bioactivity, self-assembly, structural hierarchy, applications, heart valves, skin repair, bio-design, essential ideas in biomaterials, bioactive biomaterials, bioresorbable biomaterials, biomaterials in medical practice, biomedical function for design, biomaterial properties such as biocompatibility, heat response, non-toxicity, mechanical properties, physical properties, wear, and corrosion, as well as biomaterial properties such surfaces that are antibacterial, nanostructured materials, and biofilm disrupting compounds, are all being investigated. It is technically possible to stop the spread of implant infection.
{"title":"Biomaterial types, properties, medical applications, and other factors: a recent review","authors":"Reeya Agrawal, Anjan Kumar, Mustafa K. A. Mohammed, Sangeeta Singh","doi":"10.1631/jzus.A2200403","DOIUrl":"https://doi.org/10.1631/jzus.A2200403","url":null,"abstract":"当患者体内的受损器官/组织被修复/替代后，患者的生活质量将会得到大幅改善。用于人体植入性治疗的生物材料必须具备特定的性能。人体对生物材料的接受程度是决定器官修复/移植成败的关键因素。最新的生物材料的结构应与组织内的结构相似。当前，基于先进的抗污、杀菌及抗生物膜技术，研究者正在研发抗感染的生物材料；它在现代医疗中预防和治疗重大传染性疾病是不可或缺的。这些对生物材料提出了新的要求。将来的研究热点之一是制备人体植入物的材料，并添加金属、陶瓷及聚合物。这篇综述涵盖了组织工程所需的生物材料的概念、关键特征以及生物材料（包括生物活性材料和生物可吸收材料）在医疗实践中的应用，并将会帮助研究者更好地选取生物材料。 Biomaterial research has been going on for several years, and many companies are heavily investing in new product development. However, it is a contentious field of science. Biomaterial science is a field that combines materials science and medicine. The replacement or restoration of damaged tissues or organs enhances the patient’s quality of life. The deciding aspect is whether or not the body will accept a biomaterial. A biomaterial used for an implant must possess certain qualities to survive a long time. When a biomaterial is used for an implant, it must have specific properties to be long-lasting. A variety of materials are used in biomedical applications. They are widely used today and can be used individually or in combination. This review will aid researchers in the selection and assessment of biomaterials. Before using a biomaterial, its mechanical and physical properties should be considered. Recent biomaterials have a structure that closely resembles that of tissue. Anti-infective biomaterials and surfaces are being developed using advanced antifouling, bactericidal, and antibiofilm technologies. This review tries to cover critical features of biomaterials needed for tissue engineering, such as bioactivity, self-assembly, structural hierarchy, applications, heart valves, skin repair, bio-design, essential ideas in biomaterials, bioactive biomaterials, bioresorbable biomaterials, biomaterials in medical practice, biomedical function for design, biomaterial properties such as biocompatibility, heat response, non-toxicity, mechanical properties, physical properties, wear, and corrosion, as well as biomaterial properties such surfaces that are antibacterial, nanostructured materials, and biofilm disrupting compounds, are all being investigated. It is technically possible to stop the spread of implant infection.","PeriodicalId":17508,"journal":{"name":"Journal of Zhejiang University-SCIENCE A","volume":"32 1","pages":"1 - 16"},"PeriodicalIF":3.2,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84306624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peihao Zhang, Xingshuang Lin, Hao Wang, Jia-wang Chen, Z. Tian, Zixin Weng, Ziqiang Ren, P. Zhou
目的 海底地层钻探机器人作为一种新型的海底地层地质调查手段具有广阔的应用前景。本文旨在分析并设计一种新型的自推进式螺旋钻头,以减小机器人在地层中运动时的前端阻力。 创新点 1. 通过理论建模分析,推导出新型自推进螺旋钻头的螺旋升角与土壤钻屑排出运动的关系;2. 建立仿真模型,成功模拟钻头在海底土壤中的钻进过程,并通过其贯入力和扭矩分析其自推进效果;3. 设计试验装置,成功模拟钻头在土壤中的钻进过程,并通过其贯入力和扭矩进一步验证其自推进效果。 方法 1. 通过理论推导,构建螺旋叶片升角与土壤钻屑排出运动之间的关系,得到具有设计优势的新型自推进钻头。2. 通过Abaqus有限元仿真软件,采用耦合欧拉-拉格朗日方法进行钻头钻进过程的仿真分析,可视化观察钻头钻进过程对周围土壤的扰动范围(图9);对比自推进钻头与传统锥形钻头在相同转速下轴向贯入力上的差别,确定其自推进效果的优势(图10)。3. 通过试验,进一步验证所设计的自推进钻头在配制的模拟海底土壤中的减阻钻进效果(图14)。 结论 1. 自推进钻头钻进过程对周围土壤的影响范围小于传统锥形钻头;2. 自推进钻头能够靠排出土屑提供推进力,因而有着更小的钻进阻力;3. 自推进钻头的轴向推进力随着转速的增加而不断增大,所以较高转速有着更好的钻进减阻优势;4. 自推进钻头的扭矩高于传统锥形钻头。 Robotic subsea stratum drilling robot is a method for new subsea stratigraphic geological investigation and resource exploration. Resistance at the front end is the main source of resistance to the robot’s motion in the strata. Since there is no continuous and strong downward drilling force as in conventional drilling rigs, robot movement relies heavily on the drill bit to reduce the drilling resistance. In this study we propose a self-propelling drill bit that can discharge soil debris to provide propulsive force and reduce the resistance. The key parameter of the drill bit design, the spiral blade lead angle, was determined by theoretical analysis of the drill bit’s soil discharging effect. To verify the structural advantages of the self-propelling drill bit in reducing resistance, a comparative analysis with a conventional conical drill bit was conducted. The drilling process of both bits was simulated using finite element simulation at various rotation speeds, the penetration force and torque data of both drill bits were obtained, and tests prepared accordingly in subsea soil were conducted. The simulations and tests verified that the penetration force of the self-propelling drill bit was lower than that of the conventional conical drill bit. The self-propelling drill bit can reduce the resistance effectively, and may play an important role in the stratum movement of drilling robots.
目的 海底地层钻探机器人作为一种新型的海底地层地质调查手段具有广阔的应用前景。本文旨在分析并设计一种新型的自推进式螺旋钻头,以减小机器人在地层中运动时的前端阻力。 创新点 1. 通过理论建模分析,推导出新型自推进螺旋钻头的螺旋升角与土壤钻屑排出运动的关系;2. 建立仿真模型,成功模拟钻头在海底土壤中的钻进过程,并通过其贯入力和扭矩分析其自推进效果;3. 设计试验装置,成功模拟钻头在土壤中的钻进过程,并通过其贯入力和扭矩进一步验证其自推进效果。 方法 1. 通过理论推导,构建螺旋叶片升角与土壤钻屑排出运动之间的关系,得到具有设计优势的新型自推进钻头。2. 通过Abaqus有限元仿真软件,采用耦合欧拉-拉格朗日方法进行钻头钻进过程的仿真分析,可视化观察钻头钻进过程对周围土壤的扰动范围(图9);对比自推进钻头与传统锥形钻头在相同转速下轴向贯入力上的差别,确定其自推进效果的优势(图10)。3. 通过试验,进一步验证所设计的自推进钻头在配制的模拟海底土壤中的减阻钻进效果(图14)。 结论 1. 自推进钻头钻进过程对周围土壤的影响范围小于传统锥形钻头;2. 自推进钻头能够靠排出土屑提供推进力,因而有着更小的钻进阻力;3. 自推进钻头的轴向推进力随着转速的增加而不断增大,所以较高转速有着更好的钻进减阻优势;4. 自推进钻头的扭矩高于传统锥形钻头。 Robotic subsea stratum drilling robot is a method for new subsea stratigraphic geological investigation and resource exploration. Resistance at the front end is the main source of resistance to the robot’s motion in the strata. Since there is no continuous and strong downward drilling force as in conventional drilling rigs, robot movement relies heavily on the drill bit to reduce the drilling resistance. In this study we propose a self-propelling drill bit that can discharge soil debris to provide propulsive force and reduce the resistance. The key parameter of the drill bit design, the spiral blade lead angle, was determined by theoretical analysis of the drill bit’s soil discharging effect. To verify the structural advantages of the self-propelling drill bit in reducing resistance, a comparative analysis with a conventional conical drill bit was conducted. The drilling process of both bits was simulated using finite element simulation at various rotation speeds, the penetration force and torque data of both drill bits were obtained, and tests prepared accordingly in subsea soil were conducted. The simulations and tests verified that the penetration force of the self-propelling drill bit was lower than that of the conventional conical drill bit. The self-propelling drill bit can reduce the resistance effectively, and may play an important role in the stratum movement of drilling robots.
{"title":"Design and comparative analysis of self-propelling drill bit applied to deep-sea stratum drilling robot","authors":"Peihao Zhang, Xingshuang Lin, Hao Wang, Jia-wang Chen, Z. Tian, Zixin Weng, Ziqiang Ren, P. Zhou","doi":"10.1631/jzus.A2200351","DOIUrl":"https://doi.org/10.1631/jzus.A2200351","url":null,"abstract":"目的 海底地层钻探机器人作为一种新型的海底地层地质调查手段具有广阔的应用前景。本文旨在分析并设计一种新型的自推进式螺旋钻头,以减小机器人在地层中运动时的前端阻力。 创新点 1. 通过理论建模分析,推导出新型自推进螺旋钻头的螺旋升角与土壤钻屑排出运动的关系;2. 建立仿真模型,成功模拟钻头在海底土壤中的钻进过程,并通过其贯入力和扭矩分析其自推进效果;3. 设计试验装置,成功模拟钻头在土壤中的钻进过程,并通过其贯入力和扭矩进一步验证其自推进效果。 方法 1. 通过理论推导,构建螺旋叶片升角与土壤钻屑排出运动之间的关系,得到具有设计优势的新型自推进钻头。2. 通过Abaqus有限元仿真软件,采用耦合欧拉-拉格朗日方法进行钻头钻进过程的仿真分析,可视化观察钻头钻进过程对周围土壤的扰动范围(图9);对比自推进钻头与传统锥形钻头在相同转速下轴向贯入力上的差别,确定其自推进效果的优势(图10)。3. 通过试验,进一步验证所设计的自推进钻头在配制的模拟海底土壤中的减阻钻进效果(图14)。 结论 1. 自推进钻头钻进过程对周围土壤的影响范围小于传统锥形钻头;2. 自推进钻头能够靠排出土屑提供推进力,因而有着更小的钻进阻力;3. 自推进钻头的轴向推进力随着转速的增加而不断增大,所以较高转速有着更好的钻进减阻优势;4. 自推进钻头的扭矩高于传统锥形钻头。 Robotic subsea stratum drilling robot is a method for new subsea stratigraphic geological investigation and resource exploration. Resistance at the front end is the main source of resistance to the robot’s motion in the strata. Since there is no continuous and strong downward drilling force as in conventional drilling rigs, robot movement relies heavily on the drill bit to reduce the drilling resistance. In this study we propose a self-propelling drill bit that can discharge soil debris to provide propulsive force and reduce the resistance. The key parameter of the drill bit design, the spiral blade lead angle, was determined by theoretical analysis of the drill bit’s soil discharging effect. To verify the structural advantages of the self-propelling drill bit in reducing resistance, a comparative analysis with a conventional conical drill bit was conducted. The drilling process of both bits was simulated using finite element simulation at various rotation speeds, the penetration force and torque data of both drill bits were obtained, and tests prepared accordingly in subsea soil were conducted. The simulations and tests verified that the penetration force of the self-propelling drill bit was lower than that of the conventional conical drill bit. The self-propelling drill bit can reduce the resistance effectively, and may play an important role in the stratum movement of drilling robots.","PeriodicalId":17508,"journal":{"name":"Journal of Zhejiang University-SCIENCE A","volume":"59 1","pages":"925-936"},"PeriodicalIF":3.2,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91005192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High-speed railways are very important in global transportation. However, the railway subgrade is significantly affected by the environment due to its exposure to the atmosphere. At present, global warming is the primary trend in world climate change and seriously damages railway infrastructure. Owing to the coupling effect of extreme environmental and train loads, various subgrade problems tend to arise, such as settlement, ballast fouling, and mud pumping, thus inducing frequent railway accidents and reducing travel safety. Insights into the problems triggered by extreme climate and train loads are critical to the design and long-term operation of high-speed railway subgrades. This study therefore presents a detailed survey of recent advances in typical subgrade problems through analyzing the problem formation mechanisms and influences. Traditional and emerging detection/monitoring technologies in respect of subgrade problems are discussed in detail, as well as pre-accident and post-accident maintenance methods. Finally, according to the existing challenges in long-term subgrade shakedown assessment, an outlook on open opportunities is provided for future research. 作为全球关键交通基础设施,高速铁路承担着大量的运输任务。极端气候和列车荷载的耦合作用容易诱发各种路基病害,从而导致高速铁路事故频发,极大地影响了人们的出行安全。因此,研究极端气候与列车交通耦合作用对高铁路基长期服役性能的影响具有重要意义。本文总结了当前高铁路基长期服役过程中出现的路基病害类型,针对典型病害的研究现状、路基短期检测和长期监测技术以及路基病害的控制修复手段进行回顾,指出目前研究的不足,并为今后该领域的研究提供了一定的建议。
{"title":"Impact of extreme climate and train traffic loads on the performance of high-speed railway geotechnical infrastructures","authors":"Ying Wu, Haoran Fu, X. Bian, Yunmin Chen","doi":"10.1631/jzus.A2200341","DOIUrl":"https://doi.org/10.1631/jzus.A2200341","url":null,"abstract":"High-speed railways are very important in global transportation. However, the railway subgrade is significantly affected by the environment due to its exposure to the atmosphere. At present, global warming is the primary trend in world climate change and seriously damages railway infrastructure. Owing to the coupling effect of extreme environmental and train loads, various subgrade problems tend to arise, such as settlement, ballast fouling, and mud pumping, thus inducing frequent railway accidents and reducing travel safety. Insights into the problems triggered by extreme climate and train loads are critical to the design and long-term operation of high-speed railway subgrades. This study therefore presents a detailed survey of recent advances in typical subgrade problems through analyzing the problem formation mechanisms and influences. Traditional and emerging detection/monitoring technologies in respect of subgrade problems are discussed in detail, as well as pre-accident and post-accident maintenance methods. Finally, according to the existing challenges in long-term subgrade shakedown assessment, an outlook on open opportunities is provided for future research. 作为全球关键交通基础设施,高速铁路承担着大量的运输任务。极端气候和列车荷载的耦合作用容易诱发各种路基病害,从而导致高速铁路事故频发,极大地影响了人们的出行安全。因此,研究极端气候与列车交通耦合作用对高铁路基长期服役性能的影响具有重要意义。本文总结了当前高铁路基长期服役过程中出现的路基病害类型,针对典型病害的研究现状、路基短期检测和长期监测技术以及路基病害的控制修复手段进行回顾,指出目前研究的不足,并为今后该领域的研究提供了一定的建议。","PeriodicalId":17508,"journal":{"name":"Journal of Zhejiang University-SCIENCE A","volume":"24 1","pages":"189-205"},"PeriodicalIF":3.2,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82141137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bridges are an important part of railway infrastructure and need regular inspection and maintenance. Using unmanned aerial vehicle (UAV) technology to inspect railway infrastructure is an active research issue. However, due to the large size of UAV images, flight distance, and height changes, the object scale changes dramatically. At the same time, the elements of interest in railway bridges, such as bolts and corrosion, are small and dense objects, and the sample data set is seriously unbalanced, posing great challenges to the accurate detection of defects. In this paper, an adaptive cropping shallow attention network (ACSANet) is proposed, which includes an adaptive cropping strategy for large UAV images and a shallow attention network for small object detection in limited samples. To enhance the accuracy and generalization of the model, the shallow attention network model integrates a coordinate attention (CA) mechanism module and an alpha intersection over union ( α -IOU) loss function, and then carries out defect detection on the bolts, steel surfaces, and railings of railway bridges. The test results show that the ACSANet model outperforms the YOLOv5s model using adaptive cropping strategy in terms of the total mAP (an evaluation index) and missing bolt mAP by 5% and 30%, respectively. Also, compared with the YOLOv5s model that adopts the common cropping strategy, the total mAP and missing bolt mAP are improved by 10% and 60%, respectively. Compared with the YOLOv5s model without any cropping strategy, the total mAP and missing bolt mAP are improved by 40% and 67%, respectively. 目的 桥梁钢结构以及钢结构上的高强度螺栓长期受风雨侵蚀,常常会有锈蚀或缺失的情况发生,而人工巡检的效率低、危险性大且视觉盲区多。本文期望通过无人机拍摄,对铁路桥梁钢结构图像所包含的检测目标（螺母正常、螺栓正常、螺栓缺失、螺母缺失、钢表面锈蚀和钢栏杆锈蚀）进行识别和检测,以提高铁路桥梁巡检工作的精度和效率。 创新点 1. 提出了一种自适应图像裁剪方法,可根据图像的具体情况,自适应的调整图像的分割尺寸以及裁剪重叠区域面积,可以消除无人机拍摄距离以及焦距不固定带来的负面影响,并且提高小目标的检测效果;2. 基于铁路桥梁钢结构待检测对象的特征,提出了浅层注意力网络,使模型能够更加关注待检测对象的浅层特征,从而使锈蚀区域更易于检测;3. 将坐标注意力（CA）机制模块集成到浅层注意力网络模型当中,帮助网络在大范围的无人机拍摄场景下找到缺陷区域;4. 将阿尔法并交比（α-IOU）损失函数集成到浅层注意力网络模型当中,提高针对铁路桥梁钢结构小数据集的训练和测试精度。 方法 1. 提出自适应图像裁剪策略,对无人机大尺寸图像进行处理,得到更易于网络检测出缺陷目标的小图像;2. 通过对YOLO网络进行改进,得到更关注浅层特征的浅注意力网络,提高对锈蚀、缺失的检测精度;3. 集成CA注意力机制和α-IOU损失函数到浅注意力网络中,提高图像检测的精度。 结论 1. 在小数据集中,待检测目标与输入图像的比例对最终的检测结果有明显影响;在本研究使用的数据集中,图像与主目标比例在20׃1到80׃1之间时,以50׃1为界限,大于50׃1时,精度变化较大,但是训练时间基本不变,而小于50׃1时,精度基本不变,但是训练时间变化较大,因此在训练过程中,存在一个临界点,此时训练效率和测试结果最佳。2. 更深层的网络会干扰小目标、少样本且简单特征对象的检测精度;对比其他策略相同但网络结构不同的检测结果,ACSANet相较于ACNet+CA+α-IOU的螺栓缺失精度提高了近10%。3. 不同的注意力机制由于注意方向不同,并不一定会提高检测精度;合适的注意力机制以及损失函数可以对铁路桥梁钢结构无人机图像目标进行更好的检测,采用不合适的注意力机制会对检测产生负面效果。
{"title":"Adaptive cropping shallow attention network for defect detection of bridge girder steel using unmanned aerial vehicle images","authors":"Zonghan Mu, Yong Qin, Chongchong Yu, Yunpeng Wu, Zhipeng Wang, Huaizhi Yang, Yonghui Huang","doi":"10.1631/jzus.A2200175","DOIUrl":"https://doi.org/10.1631/jzus.A2200175","url":null,"abstract":"Bridges are an important part of railway infrastructure and need regular inspection and maintenance. Using unmanned aerial vehicle (UAV) technology to inspect railway infrastructure is an active research issue. However, due to the large size of UAV images, flight distance, and height changes, the object scale changes dramatically. At the same time, the elements of interest in railway bridges, such as bolts and corrosion, are small and dense objects, and the sample data set is seriously unbalanced, posing great challenges to the accurate detection of defects. In this paper, an adaptive cropping shallow attention network (ACSANet) is proposed, which includes an adaptive cropping strategy for large UAV images and a shallow attention network for small object detection in limited samples. To enhance the accuracy and generalization of the model, the shallow attention network model integrates a coordinate attention (CA) mechanism module and an alpha intersection over union ( α -IOU) loss function, and then carries out defect detection on the bolts, steel surfaces, and railings of railway bridges. The test results show that the ACSANet model outperforms the YOLOv5s model using adaptive cropping strategy in terms of the total mAP (an evaluation index) and missing bolt mAP by 5% and 30%, respectively. Also, compared with the YOLOv5s model that adopts the common cropping strategy, the total mAP and missing bolt mAP are improved by 10% and 60%, respectively. Compared with the YOLOv5s model without any cropping strategy, the total mAP and missing bolt mAP are improved by 40% and 67%, respectively. 目的 桥梁钢结构以及钢结构上的高强度螺栓长期受风雨侵蚀,常常会有锈蚀或缺失的情况发生,而人工巡检的效率低、危险性大且视觉盲区多。本文期望通过无人机拍摄,对铁路桥梁钢结构图像所包含的检测目标（螺母正常、螺栓正常、螺栓缺失、螺母缺失、钢表面锈蚀和钢栏杆锈蚀）进行识别和检测,以提高铁路桥梁巡检工作的精度和效率。 创新点 1. 提出了一种自适应图像裁剪方法,可根据图像的具体情况,自适应的调整图像的分割尺寸以及裁剪重叠区域面积,可以消除无人机拍摄距离以及焦距不固定带来的负面影响,并且提高小目标的检测效果;2. 基于铁路桥梁钢结构待检测对象的特征,提出了浅层注意力网络,使模型能够更加关注待检测对象的浅层特征,从而使锈蚀区域更易于检测;3. 将坐标注意力（CA）机制模块集成到浅层注意力网络模型当中,帮助网络在大范围的无人机拍摄场景下找到缺陷区域;4. 将阿尔法并交比（α-IOU）损失函数集成到浅层注意力网络模型当中,提高针对铁路桥梁钢结构小数据集的训练和测试精度。 方法 1. 提出自适应图像裁剪策略,对无人机大尺寸图像进行处理,得到更易于网络检测出缺陷目标的小图像;2. 通过对YOLO网络进行改进,得到更关注浅层特征的浅注意力网络,提高对锈蚀、缺失的检测精度;3. 集成CA注意力机制和α-IOU损失函数到浅注意力网络中,提高图像检测的精度。 结论 1. 在小数据集中,待检测目标与输入图像的比例对最终的检测结果有明显影响;在本研究使用的数据集中,图像与主目标比例在20׃1到80׃1之间时,以50׃1为界限,大于50׃1时,精度变化较大,但是训练时间基本不变,而小于50׃1时,精度基本不变,但是训练时间变化较大,因此在训练过程中,存在一个临界点,此时训练效率和测试结果最佳。2. 更深层的网络会干扰小目标、少样本且简单特征对象的检测精度;对比其他策略相同但网络结构不同的检测结果,ACSANet相较于ACNet+CA+α-IOU的螺栓缺失精度提高了近10%。3. 不同的注意力机制由于注意方向不同,并不一定会提高检测精度;合适的注意力机制以及损失函数可以对铁路桥梁钢结构无人机图像目标进行更好的检测,采用不合适的注意力机制会对检测产生负面效果。","PeriodicalId":17508,"journal":{"name":"Journal of Zhejiang University-SCIENCE A","volume":"71 1","pages":"243-256"},"PeriodicalIF":3.2,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85921574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The traction drive system is the “heart” of rail transit vehicles. The development of sustainable, secure, economic, reliable, efficient, and comfortable contemporary rail transportation has led to increasingly stringent requirements for traction drive systems. The interest in such systems is constantly growing, supported by advancements such as permanent magnet (PM) motors, advanced electronic devices such as those using silicon carbide (SiC), new-generation insulating materials such as organic silicon, and advanced magnetic materials such as rare-earth magnets and amorphous materials. Progress has also been made in control methods, manufacturing technology, artificial intelligence (AI), and other advanced technologies. In this paper, we briefly review the state-of-the-art critical global trends in rail transit traction drive technology in recent years. Potential areas for research and the main obstacles hindering the development of the next-generation rail transit traction drive systems are also discussed. Finally, we describe some advanced traction drive technologies used in actual engineering applications. 牵引传动系统是轨道交通车辆的“心脏”。当代轨道交通绿色、安全、经济、可靠、高效、舒适的发展方向对牵引传动系统提出了日益苛刻的要求。永磁电机等先进电机、碳化硅等先进电子器件、有机硅等新一代绝缘材料、稀土永磁和非晶等先进磁材料和现代控制技术、先进制造技术、人工智能等高新技术的快速发展为新一代牵引传动系统提供了重要的条件支撑。本文简略回顾近年来轨道交通牵引传动技术的重要进展,并对下一代轨道交通牵引传动技术的发展方向及面临的主要挑战进行探讨。
{"title":"Recent advances in traction drive technology for rail transit","authors":"Jien Ma, Chao-qun Luo, Lin Qiu, Xing Liu, Bowen Xu, Jiabo Shou, Youtong Fang","doi":"10.1631/jzus.A2200285","DOIUrl":"https://doi.org/10.1631/jzus.A2200285","url":null,"abstract":"The traction drive system is the “heart” of rail transit vehicles. The development of sustainable, secure, economic, reliable, efficient, and comfortable contemporary rail transportation has led to increasingly stringent requirements for traction drive systems. The interest in such systems is constantly growing, supported by advancements such as permanent magnet (PM) motors, advanced electronic devices such as those using silicon carbide (SiC), new-generation insulating materials such as organic silicon, and advanced magnetic materials such as rare-earth magnets and amorphous materials. Progress has also been made in control methods, manufacturing technology, artificial intelligence (AI), and other advanced technologies. In this paper, we briefly review the state-of-the-art critical global trends in rail transit traction drive technology in recent years. Potential areas for research and the main obstacles hindering the development of the next-generation rail transit traction drive systems are also discussed. Finally, we describe some advanced traction drive technologies used in actual engineering applications. 牵引传动系统是轨道交通车辆的“心脏”。当代轨道交通绿色、安全、经济、可靠、高效、舒适的发展方向对牵引传动系统提出了日益苛刻的要求。永磁电机等先进电机、碳化硅等先进电子器件、有机硅等新一代绝缘材料、稀土永磁和非晶等先进磁材料和现代控制技术、先进制造技术、人工智能等高新技术的快速发展为新一代牵引传动系统提供了重要的条件支撑。本文简略回顾近年来轨道交通牵引传动技术的重要进展,并对下一代轨道交通牵引传动技术的发展方向及面临的主要挑战进行探讨。","PeriodicalId":17508,"journal":{"name":"Journal of Zhejiang University-SCIENCE A","volume":"29 1","pages":"177-188"},"PeriodicalIF":3.2,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76186024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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